Sunday, October 4, 2009

Problem 55 - GMAT Geometry


6 comments:

  1. Wow this is a toughie.. Ari, you are good!

    Ricardo

    ReplyDelete
  2. A(0,1,0)
    C(1,0,0)
    B(1,1,1)
    AC= (-1,1,0)
    BC = (0,1,1)
    CosC = 1/sqrt(2)^2 = 1/2
    C = 60

    The other way: notice that it is equilateral triangle formed by diagonals. Hence, 60

    ReplyDelete
  3. Good job guys. And blaoism, yes, the best way of looking at it is to see that ABC is equilateral so the angle will equal 60. And yeah, this is a real tough guy, until someone tell you how to do it! Then it iseems obvious, right?

    ReplyDelete
  4. Easier method:
    Lime from A to B is diagonal of one side of the cube.
    Same with BC and AC. Since all the faces of the cube have similar dimension, all the sides of the triangle, AB, BC, and CA are having same length.
    If all the sides are same, then it should be equilateral triangle.
    -Bharath S H

    ha

    ReplyDelete
  5. Really, these quotes are the holistic approach towards mindfulness. In fact, all of your posts are. Proudly saying I’m getting fruitfulness out of it what you write and share. Thank you so much to both of you.
    GMAT Training in Chennai
    GMAT Coaching Chennai
    Best GMAT Coaching Classes in Chennai

    ReplyDelete